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June 12, 1928. 1,673,213

T. w. SUKUMLYN VARIABLE CONDENSER Filed Oct. 29, 1925 moms N SUKUNLYN Patented June 12, 1928.

UNITED STATES THOMAS W. SUKUMLYN, OF LOS ANGELES, CALIFORNIA.

VARIABLE CONDENSER.

Application filed October 29, 1925. Serial No. 65,625.

My invention relates to variable condensers for radio apparatus of the type having a stator and rotor composed of plates, with the rotor plates rotatable to vary the capacity of the condenser. In condensers of this type as heretofore proposed, two supporting frai'nes, as well as numerous screw5, nuts and bushings, have been necessary to the proper supporting and mounting of the condenser plates on the insulating panel of a radio receiving set. Aside from the ex pense of manufacturing and assembling these parts, they greatly increase the chance of current losses through improper connedtions and insulation. j

It is a purpose of my invention to provide variable condenser of the above'type which eliminates certain parts and, reduces in number other parts necessary to' the mounting of the condenser plates on an ,insulating panel, whereby the possibility of current losses is reduced to a minimum, the manufacturing cost lowe ed, and the assembling operation renderedj cirtremely simple. '1

It is also apurpose .of my invention to provide a variablecondenser which permits of an adjustment of the condenser plates to compensate for any inaccuracies in the manufacture of the condenser and its mounting so that when in applied position the rotor plates will be properly spaced from the stator plates to produce the required di-elecinc.

'1 will describe only one form of variable comlenser embodying my invention, and will then point out the. novel features thereof in claims.

In the drawings Figure 1 is a view showing in central vertical section one form of variable condenser embodying my invention in applied position to an insulating panel;

Figures 2 and 3 are sectional views taken on the lines 22 and 33 of Figure 1.

Referring to the drawings, in which similar reference characters refer to similar parts in each of the views, my invention in its present embodiment is shown applied to the conventional panel 15 of a radio receiving set, such panel being formed of insulating material provided with an opening 16 in which is a. bushing 17 exteriorly threaded to receive a nut 18 and provided with a head 19 which co-operates with the nut to securely clamp the bushing within the opening. A shaftQO is rotatably mounted in the bushing 17; and is of such length as to extendto' the opposite sides of the panel 15, where at the outer 'side of the panel the shaft is provided with a dial 21 of insulating material bygwhich the'shaft can be manually rotated: BetWeen its ends the shaft is pi o vided with a conical bearing member 22 r'otatably fitted in thehead 19 and urged to this position by meansof the bifurcated-end inner side of 'thelfpa nel means of a screw 25, It will be understood that the bracket and] head 1Q ermit' unrestricted rotation of the bearing-22 but prevent lengthwise movement'th'ereof whereby' the shaft 20 is secured a-gainst'long'i'tudi'nal displacement, from the u h ng.

As shown inFigurel, the innerend of the shaft is exteriorly threaded, as indicated at 26, for threaded engagement with 'acollar 27 welded orothe-rwise secured to'one' ofi'a plurality fofv plates 28 constituting the rotor of the condenser. gThelfl'se'veral 'partsof the rotor are formedwith openings'to receive the shaft 20, and a nut129 engages a; threaded end of the shaft 'andabuts 'the'collar 27 to lock the rotor as a unit to the shaft.

The rotor plates are movable between stator plates 30 rigidly connected to each other and rigidly mounted on the inner side of the panel 15 through the medium of av plurality of posts 31, tubular in form and interiorly threaded to receive screws 32 which extend through the panel, as clearly shown in Figure 1.

In practice, the condenser is operated in the usual manner to vary its capacity by rotation of the shaft 20 through the medium of the dial 21 whereby the rotor plates can be moved into and out of the stator plates, the pressure exerted on the bearing by the bracket 24 operating to frictionally retain the rotor in any adjusted position. To compensate for inaccuracies in the manufacture of the parts comprising the con denser and its mounting, the rotor is adjustable longitudinally on the shaft 20 to properly space its plates with respect to the plates of the stator to set up the required di-electric. This adjustment of the rotor can be effected by first unscrewing the nut 29 to disengage the collar 27 whereby the shaft 20, upon being rotated while holding the rotor, causes the latter to be fed longi tudinally on the shaft in one direction or the other, depending upon the direction of rotation of the shaft. In this manner longitudinal adjustment of the rotor plates 28 is effected s0 that'they are all disposed in spaced parallel reation to the plates of the stator. Current may be supplied to the condenser through terminals 33 and 3'1? welded, respectively to the bracket Mend the stator ,30. g

If it is desired to dismount the condenser or any reason, it will be manifest "that By removing the bracket 24- and the [dial scribed only one "form; of vari 'ible condenser embodying my iiiye'ritionpit is to. be underspirit and 'slcopeof the ilip iiflQfl clttliiljf Iclaimi 1. In combination, a panel, a variable condenser i cluding a stato'r'an'd a' "ro t or, and means for mounting the condenser "on the panel for actuating the ifotor' 'eomp ris ing from the spifit of the invention and the ing a shaft rotatable in the"paiiel,."c1tg; ;h5

able means sjeciirf to the panel for secii r ing the shaft a ainst 'di s'bla ement' zfiam' the panel, and 'a connei'itibn the shaft and rotor by which the rotorfean be ad'- jnsted longitudinally to Vai'ythespacing of its plates with respect to the stator plates.

2. In combination, a panel, a variable condenserincluding-a "stator and a rotor, and

means for i'nounting the condenseron the panel for actuating the rotor comprising a shaft rotatable in the panel, detachable means for securing the shaft against dis placement fromthe panel, and a threaded connection between the shaft and rotor by Whiehfthe rotoi: can be adjusted 'longituclinally fto'vary the spacing of its plates with respect to: the statorfplates. I 1

3. A: variable 'e'ondenscr 'cg'in'i'prising a bushing adapte'cl'toehgagewithin the o ehing of a panel and nut detachable from one end otthe bushing and head ffilnld on the other end ot'the bushing, a rot'atable in the b hing having fa'ic'oni'eal a ngme b eeply fitte in w a-d ia'l' on one 'enth'o'f she-ft, a rotor threaded on" th v v iaftjtjo peifin it 7 ti'st n'en'l' ther'of loiigitlidiiially'o'n thes'ha'ft, a nut engaging the .rotorto lock theilitter in any adjusted positio'mia bradlgetadapted toj b e detach ably secured tothe' panel and having a bifurcated endiifeceiyingthe. shaft'and enthe"beafingf fiieinber to co-operate with the head 'i1n,;scu1j{ing the shaft against longitudinal moi emeiit, astatoi, posts fixed to the stator, andifasteningmembers adapted m extend; thfonjgflithe pa el and erg-11 ing said posts for 'ii'gidlys'eilrihg the stator toithe-panel.

- THOMAS SUKUMLYN. 

